For example, in an optical disk apparatus into which a disk-like recording medium such as a CD, a DVD and a Blu-Ray is loaded, there are an electric tray system in which the disk-like recording medium is placed on a tray and the disk-like recording medium is pulled into the apparatus by an electric motor, a direct slot-in system in which the disk-like recording medium is inserted directly into a disk insertion opening, and a slim tray system in which a disk rotating mechanism of the apparatus is pulled cut from the apparatus, and the disk-like recording medium is directly placed on a turntable by a ball-chucking. As the electric tray system, there is, in a portion of a home electrical appliance field, or an information equipment field, an electric tray system which can handle an exclusive cartridge having a shutter mechanism or which can handle a cartridge in which a medium is placed in a case, the case is placed on a tray and is loaded into the cartridge, a shutter mechanism is opened or closed by a mechanism of an apparatus, thereby operating the apparatus. As a cartridge which can be handled by a cartridge-compliant electric tray system, there are a DVD-RAM standard cartridge which is currently predominate in the market, and a BD Ver.1-exclusive cartridge which was employed in an initial. Bit-Ray disk recording apparatus. However, in recent years, a coating technique of a recording surface of a Blu-Ray disk is advanced, a bare disk is predominate, it becomes difficult to obtain this cartridge and the price thereof is high.